Effects of silica dust inhalation on the susceptibility of mice to influenza infection.

Mice were exposed to silica dust for durations of up to 36 wk. At intervals of 15, 21, 27, 33, and 36 wk, the ability of the splenic lymphocytes to respond to T and B cell mitogens were determined, and their ability to resist influenza virus infections was determined after 3 and 20 wk of exposure. These exposures had a depressing effect on the response to T cell mitogens at 21 and 27 wk of silica exposure, but there was no effect on the T cell responses after 15, 33, and 36 wk or on B cell responses after all exposure times. No changes could be detected in the ability of the mice to resist pulmonary influenza virus infections or in the survivors ability to form HI antibodies against this virus.